The present invention relates to a disposable diaper including a pair of elasticized barrier cuffs.
Disposable diapers including a pair of barrier cuffs elastically biased to be raised from the inner surface of the diaper have conventionally been well known. Specifically, such cuffs are raised from the inner surface of the diaper as elastic members attached in a stretched state to the diaper contract. Rising up in this manner, the cuffs function to prevent body fluid discharged on the inner surface of the diaper from leaking sideways.
For example, a disposable diaper disclosed in Japanese Unexamined Patent Application Publication No. 1989-162807 (REFERENCE 1) is provided in a crotch region with a pair of floating inner cuffs extending in a longitudinal direction. Each of these floating inner cuffs comprises a cuff layer defined by a part of topsheet, a base layer underlying the cuff layer and an elastic member sandwiched between the cuff layer and the base layer so as to extend in the longitudinal direction in a contractible manner. The elastic member is partially bonded to the base layer and the segment of the elastic member left free from the base layer functions to lift the cuff layer off from the base layer as this segment contracts. The cuff layer is bonded in its region a predetermined dimension spaced from the elastic member in a transverse direction of the diaper to the base layer. When lifted in this manner, the cuff layer describes an inverted V-shaped cross-section and thereby forms a double wall barrier cuff comprising walls lying inwardly and outwardly as viewed in a transverse direction of the diaper.
A disposable diaper disclosed in Japanese Unexamined Patent Application Publication No. 1989-213402 (REFERENCE 2) comprises a first sheet including side flaps put in close contact with the wearer's skin and a second sheet underlying the first sheet wherein each of the side flaps is provided in the vicinity of its outer side edge with a first elastic member and between the first elastic member and a liquid-absorbent core with a second elastic member. The first sheet is bonded in its two regions spaced from the second elastic member in opposite directions to the second sheet so that the first sheet may protuberate between these two regions as the second elastic member contracts. Consequentially, the first sheet forms a double wall barrier cuff comprising walls lying inwardly and outwardly as viewed in the transverse direction of the diaper.
The elasticized double wall barrier cuffs disclosed in REFERENCES 1 and 2 are respectively constructed in the manner that the elastic members are sandwiched between two sheets defining the inner walls and the outer walls as viewed in the transverse direction of the diaper, respectively, on transversely opposite lateral zones of the diaper so that these elastic members may lift the inner walls from below. According to such construction, a height of these barrier cuffs depends on the transversely opposite lateral zones of the diaper. It is desired to increase a height of the barrier cuffs, the transversely opposite lateral zones, particularly in the crotch region must be widened. However, any intention to widen a dimension of the crotch region is constrained by the essential condition for design. In order to increase a height of the barrier cuffs with the knowledge of such constraint, a width dimension of the body fluid absorbent core laid in the crotch region should be inevitably reduced. With the diaper having such narrow core, a capacity of the body fluid absorption in the crotch region is generally deteriorated. Therefore, it is an object of the present invention to solve the problem left behind unsolved by the prior art concerning the double wall barrier cuffs.